Housing and allergens: a pooled analysis of nine US studies

Racial differences in odds of asthma exacerbations among Aspergillus fumigatus-sensitized adults with asthma

BACKGROUND

Allergic sensitization to mold is a risk factor for poor asthma outcomes, but whether it accounts for disparities in asthma outcomes according to race or socioeconomic status is not well-studied.

OBJECTIVE

To identify factors associated with allergic sensitization to molds and evaluate associations of sensitization to molds with asthma exacerbations after stratifying by race.

METHODS

We conducted a retrospective cohort study of adults with asthma who had an outpatient visit to a large health system between January 1, 2017 and June 30, 2023 and received aeroallergen testing to Aspergillus fumigatus, Penicillium, Alternaria, and Cladosporium. We used logistic regression models to evaluate factors associated with mold sensitization and the effect of mold sensitization on asthma exacerbations in the 12 months before testing, overall and then stratified by race.

RESULTS

A total of 2732 patients met the inclusion criteria. Sensitization to each mold was negatively associated with being a woman (odds ratios [ORs] ≤ 0.59, P ≤ .001 in 5 models) and positively associated with the Black race (ORs ≥ 2.16 vs White, P < .0005 in 5 models). In the full cohort, sensitization to molds was not associated with asthma exacerbations (ORs = 0.95-1.40, P ≥ .003 in 5 models and all above the corrected P value threshold). Among 1032 Black patients, sensitization to A fumigatus, but not to other molds, was associated with increased odds of asthma exacerbations (OR = 2.04, P < .0005).

CONCLUSION

Being a man and Black race were associated with allergic sensitization to molds. Sensitization to A fumigatus was associated with asthma exacerbations among Black patients but not the overall cohort, suggesting that A fumigatus allergy is a source of disparities in asthma outcomes according to race.

A multi-city study of indoor air quality in green vs non-green low-income housing

OBJECTIVES

The condition of the home is a strong predictor of exposure to environmental contaminants, with low-income households being particularly vulnerable. Therefore, improving housing standards is a priority. Housing built to "green" standards, with improved building methods and materials, has been suggested to reduce contaminants. However, evidence is limited as to which contaminants are reduced. The Green Housing Study was conducted to address this issue. The study hypothesis was that housing built using green components has lower concentrations of environmental contaminants compared to conventional housing.

METHODS

A repeated-measures, 12-month cohort study was performed in three U.S. cities. Data were collected in the home at three time points throughout a year. The level of contaminants were estimated using air samples for particulate matter and black carbon, dust samples for aeroallergens and pesticides, and resident or study staff reporting evidence of mold. To investigate source(s) of PM2.5 and black carbon, multivariable models using stepwise variable selection were developed.

RESULTS

In adjusted generalized estimating equations (GEE) models, black carbon concentration (μg/m3) (β = -0.22, 95% CI = -0.38 to -0.06, p = 0.01), permethrin (OR = 0.28, 95% CI = 0.15-0.49, p < 0.0001), and reported mold (OR = 0.29, 95% CI = 0.13-0.68, p = 0.003) were significantly lower in green homes. Cockroach antigen was also lower in green homes (OR = 0.59, 95% CI = 0.33-1.08, p = 0.09), although not statistically significant. We found that 68% of PM2.5 was explained by dwelling type and smoking and 42% of black carbon was explained by venting while cooking and use of a gas stove.

CONCLUSIONS

This study provides quantitative data suggesting benefits of incorporating green building practices on the level of numerous environmental contaminants known to be associated with health. Occupant behavior, particularly smoking, is an important contributor to indoor air pollution.

Multilevel Risk Factors for Sleep-Disordered Breathing-Related Symptom Burden in an Urban Pediatric Community-Based Sample

BACKGROUND

Pediatric sleep-disordered breathing (SDB) disproportionately affects children with low socioeconomic status (SES). The multilevel risk factors that drive these associations are not well understood.

RESEARCH QUESTION

What are the associations between SDB risk factors, including individual health conditions (obesity, asthma, and allergies), household SES (maternal education), indoor exposures (environmental tobacco smoke [ETS] and pests), and neighborhood characteristics (neighborhood disadvantage), and pediatric SDB symptoms?

STUDY DESIGN AND METHODS

Cross-sectional analyses were performed on 303 children (aged 6-12 years) enrolled in the Environmental Assessment of Sleep Youth study from 2018 to 2022. Exposures were determined by caregiver reports, assays of measured settled dust from the child's bedroom, and neighborhood-level Census data (deriving the Childhood Opportunity Index to characterize neighborhood disadvantage). The primary outcome was the SDB-related symptom burden assessed by the OSA-18 questionnaire total score. Using linear regression models, we calculated associations between exposures and SDB-related symptom burden, adjusting for sociodemographic factors, then health conditions, indoor environment, and neighborhood factors.

RESULTS

The sample included 303 children (39% Hispanic, Latino, Latina, or Spanish origin; 30% Black or African American; 22% White; and 11% other). Increasing OSA-18 total scores were associated with low household SES after adjustment for demographic factors, and with asthma, allergies, ETS, pests (mouse, cockroach, and rodents), and an indoor environmental index (sum of the presence of pests and ETS; 0-2) after adjusting for sociodemographic factors. Even after further adjusting for asthma, allergies, and neighborhood disadvantage, ETS and pest exposure were associated with OSA-18 (ETS: β = 12.80; 95% CI, 7.07-18.53, also adjusted for pest; pest exposure: β = 3.69; 95% CI, 0.44-6.94, also adjusted for ETS).

INTERPRETATION

In addition to associations with ETS, a novel association was observed for indoor pest exposure and SDB symptom burden. Strategies to reduce household exposure to ETS and indoor allergens should be tested as approaches for reducing sleep health disparities.

Disparities in Disease Burden and Treatment of Patients Asthma and Chronic Obstructive Pulmonary Disease

Lung health reflects the inequities of our society. Asthma and chronic obstructive pulmonary disease are 2 lung conditions commonly treated in general clinical practice; each imposes a disproportionate burden on disadvantaged patients. Numerous factors mediate disparities in lung health, including air pollution, allergen exposures, tobacco, and respiratory infections. Members of racial/ethnic minorities and those of low socioeconomic status also have inferior access to high-quality medical care, compounding disparities in disease burden. Physicians can work against disparities in their practice, but wide-ranging policy reforms to achieve better air quality, housing, workplace safety, and healthcare for all are needed to achieve equity in lung health.

In-home environmental exposures predicted from geospatial characteristics of the built environment and electronic health records of children with asthma

PURPOSE

Children may be exposed to numerous in-home environmental exposures (IHEE) that trigger asthma exacerbations. Spatially linking social and environmental exposures to electronic health records (EHR) can aid exposure assessment, epidemiology, and clinical treatment, but EHR data on exposures are missing for many children with asthma. To address the issue, we predicted presence of indoor asthma trigger allergens, and estimated effects of their key geospatial predictors.

METHODS

Our study samples were comprised of children with asthma who provided self-reported IHEE data in EHR at a safety-net hospital in New England during 2004-2015. We used an ensemble machine learning algorithm and 86 multilevel features (e.g., individual, housing, neighborhood) to predict presence of cockroaches, rodents (mice or rats), mold, and bedroom carpeting/rugs in homes. We reduced dimensionality via elastic net regression and estimated effects by the G-computation causal inference method.

RESULTS

Our models reasonably predicted presence of cockroaches (area under receiver operating curves [AUC] = 0.65), rodents (AUC = 0.64), and bedroom carpeting/rugs (AUC = 0.64), but not mold (AUC = 0.54). In models adjusted for confounders, higher average household sizes in census tracts were associated with more reports of pests (cockroaches and rodents). Tax-exempt parcels were associated with more reports of cockroaches in homes. Living in a White-segregated neighborhood was linked with lower reported rodent presence, and mixed residential/commercial housing and newer buildings were associated with more reports of bedroom carpeting/rugs in bedrooms.

CONCLUSIONS

We innovatively applied a machine learning and causal inference mixture methodology to detail IHEE among children with asthma using EHR and geospatial data, which could have wide applicability and utility.

Housing and asthma disparities

The burden of asthma disproportionately affects minority and low-income communities, resulting in racial and socioeconomic disparities in asthma prevalence, asthma exacerbations, and asthma-related death. Social determinants of health are increasingly implicated as root causes of disparities, and healthy housing is perhaps the most critical social determinant in asthma health disparities. In many minority communities, poor housing conditions and value are a legacy of historical policies and practices imbued with structural racism, including redlining, displacement, and exclusionary zoning. As a result, poor-quality, substandard housing is a characteristic feature of many underrepresented minority communities. Consequently, structurally deficient housing stock cultivates home environments rife with indoor asthma triggers. In this review we consider the historical context of urban housing policies and practices and how these policies and practices have contributed to the substandard housing conditions for many minoritized children in the present day. We describe the impact of poor housing quality on asthma and interventions that have attempted to mitigate its influence on asthma symptoms and health care utilization. We discuss the need to promote asthma health equity by reinvesting in these neighborhoods and communities to provide healthy housing.

Does Public Housing Increase the Risk of Child Health Problems? Evidence from Linked Survey-Administrative Data

Research on the effects of major federal housing assistance programs on children's outcomes has produced mixed results. Although housing assistance programs provide one of the few sources of affordable and stable housing for low-income families, there remains concern that living in public housing developments increases the risk of poor health for children. This paper uses a unique survey-administrative linked dataset to examine the effect of living in public housing on children's risk of health problems, including frequent diarrhea, frequent headaches, skin allergies, asthma, and fair/poor health status. Children living in public housing have substantially more health problems than children who do not live in public housing. However, the analysis develops several additional comparison groups to demonstrate that the excess health problems reflect unobserved selection into public housing. The main selection adjustment compares children living in public housing to children who enter public housing in the near future. Results indicate that public housing does not increase the risk of child health problems, and it is important to consider the substantial selection into public housing on factors that are likely to be correlated with children's outcomes. The broad effects of public housing may be mixed, but policymakers should not confuse the economic and health challenges of public housing residents for the effects of the program itself.

The Role of Dust Mites in Allergy

House dust mites are an unsurpassed cause of atopic sensitization and allergic illness throughout the world. The major allergenic dust mites Dermatophagoides pteronyssinus, Dermatophagoides farinae, Euroglyphus maynei, and Blomia tropicalis are eight-legged members of the Arachnid class. Their approximately 3-month lifespan comprises egg, larval, protonymph, tritonymph, and adult stages, with adults, about one fourth to one third of a millimeter in size, being at the threshold of visibility. The geographic and seasonal distributions of dust mites are determined by their need for adequate humidity, while their distribution within substrates is further determined by their avoidance of light. By contacting the epithelium of the eyes, nose, lower airways, skin, and gut, the allergen-containing particles of dust mites can induce sensitization and atopic symptoms in those organs. Various mite allergens, contained primarily in mite fecal particles but also in shed mite exoskeletons and decaying mite body fragments, have properties that include proteolytic activity, homology with the lipopolysaccharide-binding component of Toll-like receptor 4, homology with other invertebrate tropomyosins, and chitin-cleaving and chitin-binding activity. Mite proteases have direct epithelial effects including the breaching of tight junctions and the stimulation of protease-activated receptors, the latter inducing pruritus, epithelial dysfunction, and cytokine release. Other components, including chitin, unmethylated mite and bacterial DNA, and endotoxin, activate pattern recognition receptors of the innate immune system and act as adjuvants promoting sensitization to mite and other allergens. Clinical conditions resulting from mite sensitization and exposure include rhinitis, sinusitis, conjunctivitis, asthma, and atopic dermatitis. Systemic allergy symptoms can also occur from the ingestion of cross-reacting invertebrates, such as shrimp or snail, or from the accidental ingestion of mite-contaminated foods. Beyond their direct importance as a major allergen source, an understanding of dust mites leads to insights into the nature of atopy and of allergic sensitization in general.

Ten questions concerning the implications of carpet on indoor chemistry and microbiology

Carpet and rugs currently represent about half of the United States flooring market and offer many benefits as a flooring type. How carpets influence our exposure to both microorganisms and chemicals in indoor environments has important health implications but is not well understood. The goal of this manuscript is to consolidate what is known about how carpet impacts indoor chemistry and microbiology, as well as to identify the important research gaps that remain. After describing the current use of carpet indoors, questions focus on five specific areas: 1) indoor chemistry, 2) indoor microbiology, 3) resuspension and exposure, 4) current practices and future needs, and 5) sustainability. Overall, it is clear that carpet can influence our exposures to particles and volatile compounds in the indoor environment by acting as a direct source, as a reservoir of environmental contaminants, and as a surface supporting chemical and biological transformations. However, the health implications of these processes are not well known, nor how cleaning practices could be optimized to minimize potential negative impacts. Current standards and recommendations focus largely on carpets as a primary source of chemicals and on limiting moisture that would support microbial growth. Future research should consider enhancing knowledge related to the impact of carpet in the indoor environment and how we might improve the design and maintenance of this common material to reduce our exposure to harmful contaminants while retaining the benefits to consumers.

Common allergies in urban adolescents and their relationships with asthma control and healthcare utilization

BACKGROUND

Urban adolescents suffer a disproportionate burden of asthma morbidity, often in association with allergies. Literature is limited on comparing various types of allergies regarding prevalence and associations with asthma morbidity in urban dwelling adolescents. The purpose of this study was to examine the prevalence of common allergies reported by urban adolescents and to assess their relationships to healthcare utilization and asthma control.

METHODS

Study participants included 313 urban adolescents (12-20 years of age) with persistent asthma who were recruited from three states in the United States. Self-report data were collected on nine indoor and outdoor allergies, healthcare utilization, and asthma exacerbation. Logistic regressions and zero-inflated Poisson regressions were conducted to examine the relationships between allergies and asthma morbidity.

RESULTS

The mean age of participants was 14.58 (± 1.97) and 52% were female, and 79% were black. Seventy-three percent (n = 229) reported one or more allergies. Dust mite and grass allergies were most common, each reported by 50%. The prevalence of pest allergies (cockroach and mouse) was 27.5% and 19%, respectively. Those with pest allergies were more likely to report ED visits (cockroach- Odds Ratio (OR) = 2.16, 95% CI 1.18-3.94, p = .01; mouse- OR = 2.13, 95% CI 1.09-4.07, p = .02), specialist visits (cockroach-OR = 2.69, 95% CI 1.60-4.54, p < .001; mouse- OR = 2.06, 95% CI 1.15-3.68, p = .01) and asthma exacerbation (cockroach-OR = 2.17, 95% CI 1.26-3.74, p < .001; mouse- OR = 2.30, 95% CI 1.26-4.18, p = .01). Cockroach allergies were associated with 2.2 times as many nights in the hospital (95% CI 1.053-3.398, p = 0.036) and 2.2 times as many specialist visits (95% CI 1.489-3.110, p < 0.001), and mouse allergy was associated with 1.6 times as many ED visits (95% CI 1.092-2.257, p = 0.015) compared to those without pest allergies.

CONCLUSIONS

Concomitant occurrence of allergies is ubiquitous among urban adolescents with asthma. Only pest allergies, of those examined, appear to have implications for poorly controlled asthma, exacerbation and acute healthcare utilization. To reduce asthma burden in urban adolescents, identification and management of high-risk adolescents with pest allergen sensitization and exposure are warranted.

Bedroom Allergen Exposure Beyond House Dust Mites

PURPOSE OF REVIEW

The review provides insight into recent findings on bedroom allergen exposures, primarily focusing on pet, pest, and fungal exposures.

RECENT FINDINGS

Large-scale studies and improved exposure assessment technologies, including measurement of airborne allergens and of multiple allergens simultaneously, have extended our understanding of indoor allergen exposures and their impact on allergic disease. Practical, streamlined methods for exposure reduction have shown promise in some settings, and potential protective effects of early-life exposures have been further elucidated through the investigation of specific bacterial taxa. Advances in molecular allergology have yielded novel data on sensitization profiles and cross-reactivity. The role of indoor allergen exposures in allergic disease is complex and remains incompletely understood. Advancing our knowledge of various co-exposures, including the environmental and host microbiome, that interact with allergens in early life will be crucial for the development of efficacious interventions to reduce the substantial economic and social burden of allergic diseases including asthma.

An Evaluation of a State-Funded Healthy Homes Intervention on Asthma Outcomes in Adults and Children

CONTEXT

Reducing exposure to environmental triggers is a critical part of asthma management.

OBJECTIVE

To evaluate the impact of a healthy homes intervention on asthma outcomes and assess the impact of different targeting strategies.

SETTING

The New York State (NYS) Healthy Neighborhoods Program (HNP) operates in select communities with a higher burden of housing-related illness and associated risk factors.

PARTICIPANTS

Residents with asthma were recruited through 3 mechanisms: door-to-door canvassing (CANVASSED), 752 residents in 457 dwellings; referrals from community partners (REFERRED), 573 residents in 307 dwellings; referrals of Medicaid enrollees with poorly controlled asthma (TARGETED), 140 residents in 140 dwellings.

INTERVENTION

The NYS HNP provides visual assessments and low-cost interventions to identify and address asthma triggers and trigger-promoting conditions in the home environment. Conditions are reassessed during a revisit conducted 3 to 6 months after the initial visit.

MAIN OUTCOME MEASURE(S)

The analysis compares improvements across the 3 groups for measures of asthma self-management, health care access, morbidity, and environmental conditions. An asthma trigger score characterizing the extent of multiple triggers in a dwelling was also calculated.

RESULTS

Among 1465 adults and children, there were significant improvements in environmental conditions and self-reported self-management, health care access, and asthma morbidity outcomes for each group. The improvement was greatest in the TARGETED group for most outcomes, but selected measures of self-management and health care access were greater in the other groups. The mean improvement was significantly greater in the TARGETED group.

CONCLUSION

Targeting the intervention to people with poorly controlled asthma maximizes improvements in trigger avoidance and asthma morbidity; however, other recruitment strategies are effective for impacting endpoints related to health care access and self-management. This evaluation demonstrates that a low-intensity home-based environmental intervention is effective as well as practical and feasible. Health care payers, state and local health departments, and others should consider investing in these home-based services as part of a comprehensive asthma care package.

Bedroom allergen exposures in US households

BACKGROUND

Bedroom allergen exposures contribute to allergic disease morbidity because people spend considerable time in bedrooms, where they come into close contact with allergen reservoirs.

OBJECTIVE

We investigated participant and housing characteristics, including sociodemographic, regional, and climatic factors, associated with bedroom allergen exposures in a nationally representative sample of the US population.

METHODS

Data were obtained from National Health and Nutrition Examination Survey 2005-2006. Information on participant and housing characteristics was collected by using questionnaires and environmental assessments. Concentrations of 8 indoor allergens (Alt a 1, Bla g 1, Can f 1, Fel d 1, Der f 1, Der p 1, Mus m 1, and Rat n 1) in dust vacuumed from nearly 7000 bedrooms were measured by using immunoassays. Exposure levels were classified as increased based on percentile (75th/90th) cutoffs. We estimated the burden of exposure to multiple allergens and used multivariable logistic regression to identify independent predictors for each allergen and household allergen burden.

RESULTS

Almost all participants (>99%) had at least 1 and 74.2% had 3 to 6 allergens detected. More than two thirds of participants (72.9%) had at least 1 allergen and 18.2% had 3 or more allergens exceeding increased levels. Although exposure variability showed significant racial/ethnic and regional differences, high exposure burden to multiple allergens was most consistently associated with the presence of pets and pests, living in mobile homes/trailers and older and rental homes, and living in nonmetropolitan areas.

CONCLUSIONS

Exposure to multiple allergens is common. Despite highly variable exposures, bedroom allergen burden is strongly associated with the presence of pets and pests.

Use of Medicaid and housing data may help target areas of high asthma prevalence

OBJECTIVE

To determine if there was a significant difference between mold contamination and asthma prevalence in Detroit and non-Detroit Michigan homes, between newer and older homes, and if there is a correlation between mold contamination and measures of Medicaid use for asthma in the 25 Detroit zip codes.

METHODS

Settled dust was collected from homes (n = 113) of Detroit asthmatic children and from a representative group of Michigan homes (n = 43). The mold contamination for each home was measured using the Environmental Relative Moldiness Index (ERMI) scale and the mean ERMI values in Detroit and non-Detroit homes were statistically compared. Michigan Medicaid data (13 measures related to asthma) in each of the 25 zip codes in Detroit were tested for correlation to ERMI values for homes in those zip codes.

RESULTS

The mean ERMI value (14.5 ± 8.0) for Detroit asthmatic childrens' homes was significantly (Student's t-test, p < 0.001) greater than the mean ERMI value (2.1 ± 6.2) for the non-Detroit homes. Detroit homes > 60 years old had significantly (p = 0.01) greater mean ERMI values than Detroit homes ≤ 60 years old (15.87 vs. 11.25). The percentage of children that underwent spirometry testing for their persistent asthma (based on Medicaid data) was significantly, positively correlated with the mean ERMI values of the homes in the 25 zip codes.

CONCLUSIONS

Applying Medicaid-use data for spirometry testing and locating a city's older housing stock might help find foci of homes with high ERMI values.

Procedures to Assist Health Care Providers to Determine When Home Assessments for Potential Mold Exposure Are Warranted

Drawing evidence from epidemiology and exposure assessment studies and recommendations from expert practice, we describe a process to guide health care providers helping their patients who present with symptoms that might be associated with living in damp housing. We present the procedures in the form of a guided 2-part interview. The first part has 5 questions that triage the patient toward a more detailed questionnaire that reflects features of housing conditions known to be reliably associated with exposures to mold and dampness contaminants. We chose the questions based on the conditions associated with moisture problems in homes across the United States and Canada. The goal is to facilitate the clinician's effort to help patients reduce exposure to environmental triggers that elicit symptoms to better manage their disease.

Prevalence of Residential Dampness and Mold Exposure in a University Student Population

The impact of residential dampness or mold on respiratory health is well established but few studies have focused on university students. This study aims to: (a) describe the prevalence of exposure to residential dampness or mold in university students according to socio-geographic factors and (b) identify associated housing characteristics. A web survey was conducted in 2014 among the 26,676 students registered at the Université de Sherbrooke (QC, Canada). Residential dampness and mold being closely intertwined, they were considered as a single exposure and assessed using a validated questionnaire. Exposure was compared according to socio-geographic and housing characteristics using chi-square tests and logistic regressions. Among the 2097 participants included in the study (response rate: 8.1%), over 80% were tenants. Residential exposure to dampness or mold was frequent (36.0%, 95% CI: 33.9-38.1). Marked differences for this exposure were noted according to home ownership (39.7% vs. 25.5% among tenants and owners respectively; OR = 1.92%, 95% CI: 1.54-2.38). Campus affiliation, household composition and the number of residents per building were associated with exposure to dampness or mold (p < 0.01), while sex and age were not. Exposure was also associated with older buildings, and buildings in need of renovations and lacking proper ventilation (p < 0.001). This study highlights the potential risk of university students suffering from mold-related health effects given their frequent exposure to this agent. Further research is needed to fully evaluate the mold-related health impact in this at risk group.

Allergen sensitization profiles in a population-based cohort of children hospitalized for asthma

RATIONALE

Allergen sensitization is associated with asthma morbidity. A better understanding of allergen sensitization patterns among children hospitalized for asthma could help clinicians tailor care more effectively. To our knowledge, however, sensitization profiles among children hospitalized for asthma are unknown.

OBJECTIVES

We sought to describe allergen sensitization profiles and the distribution of self-reported in-home exposures among children hospitalized for asthma. We also sought to assess how sensitization profiles varied by sociodemographic and clinical factors.

METHODS

This population-based cohort study includes data for 478 children, aged 4-16 years, hospitalized for an asthma exacerbation. Predictors included child age, race, sex, insurance status, reported income, salivary cotinine, exposure to traffic-related air pollution, asthma and atopic history, and season of admission. Outcomes included serum IgE specific to Alternaria alternata/A. tenuis, Aspergillus fumigatus, American cockroach, mouse epithelium, dust mite (Dermatophagoides pteronyssinus and farinae), cat dander, and dog dander (deemed sensitive if IgE ≥ 0.35). Self-reported adverse exposures included mold/mildew, water leaks, cockroaches, rodents, and cracks or holes in the walls or ceiling. Presence of carpeting and furry pets was also assessed.

MEASUREMENTS AND MAIN RESULTS

More than 50% of included patients were sensitized to each of Alternaria, Aspergillus, dust mite, cat dander, and dog dander; 28% were sensitized to cockroach and 18% to mouse. Roughly 68% were sensitized to three or more allergens with evidence of clustering. African American children, compared with white children, were more likely to be sensitized to Alternaria, Aspergillus, cockroach, and dust mite (all P<0.01). White children were more likely to be sensitized to mouse, cat, and dog (all P<0.01). Lower income was associated with cockroach sensitization whereas higher income was associated with dog and cat sensitization (all P<0.01). Atopic history was associated with sensitization to three or more allergens (P<0.01). Although 42% reported exposure to at least one adverse in-home exposure (and 72% to carpet, 51% to furry pets), only weak relationships were seen between reported exposures and sensitizations.

CONCLUSIONS

Most children admitted to the hospital for asthma exacerbations are sensitized to multiple indoor allergens. Atopy on the inpatient unit serves as a potential target for improvement in chronic asthma management.

Health Benefits of Green Public Housing: Associations With Asthma Morbidity and Building-Related Symptoms

OBJECTIVES

We examined associations of several health outcomes with green and conventional low-income housing, where the prevalence of morbidities and environmental pollutants is elevated.

METHODS

We used questionnaires and a visual inspection to compare sick building syndrome (SBS) symptoms and asthma-related morbidity among residents in multifamily units in Boston, Massachusetts, between March 2012 and May 2013. Follow-up was approximately 1 year later.

RESULTS

Adults living in green units reported 1.35 (95% confidence interval [CI] = 0.66, 2.05) fewer SBS symptoms than those living in conventional (control) homes (P < .001). Furthermore, asthmatic children living in green homes experienced substantially lower risk of asthma symptoms (odds ratio [OR] = 0.34; 95% CI = 0.12, 1.00), asthma attacks (OR = 0.31; 95% CI = 0.11, 0.88), hospital visits (OR = 0.24; 95% CI = 0.06, 0.88), and asthma-related school absences (OR = 0.21; 95% CI = 0.06, 0.74) than children living in conventional public housing.

CONCLUSIONS

Participants living in green homes had improved health outcomes, which remained consistent over the study period. Green housing may provide a significant value in resource-poor settings where green construction or renovation could simultaneously reduce harmful indoor exposures, promote resident health, and reduce operational costs.

Impact of a multi-trigger intervention on seasonal patterns of asthma symptoms in inner city children

OBJECTIVES

Peaks in childhood asthma symptoms and asthma morbidity occur universally in the fall and late winter/early spring. This study examines whether there is a time of the year best suited to implement environmental interventions to attenuate this pattern.

METHODS

From September 2006 to June 2010, mid-Atlantic inner-city children asthmatics with 1 asthma-related hospitalization (IP) or 2 emergency (ED) visits the year prior to enrollment received 5 in-home self-management education sessions which included multi-trigger avoidance techniques and supplies. Children's daily asthma symptoms were recorded for 12 months by caregivers.

RESULTS

One-hundred and thirty-six children (48%) completed 12 months of symptoms diaries. Symptom days were reduced by 4.5 days at 12 months follow-up (p < 0.001). Symptom severity improved with a decreased severity score of 29.0 to 7.9 at month 12 (p < 0.001). Sixty-one percent of patients with ≥2 ED visits at baseline dropped to 0-1visits (p < 0.001). Eighty percent of patients with ≥1 IP visits dropped to 0 visits at 12 months (p < 0.001). Patients who received intervention in the summer months had half the average monthly symptoms score (10.8) as those who received intervention in the spring months (20.8). When controlling for environment and morbidity, the summer enrolled group had a significantly lower (p = 0.021) symptom score than those in other seasons.

CONCLUSION

Home self-management/environmental interventions for this cohort appear to have the greatest effect for those receiving the intervention in the summer and fall. The largest impact occurs in the summer cohort. Further studies with a control group are necessary to confirm these findings.

Inner city asthma

The inner city has long been recognized as an area of high asthma morbidity and mortality. A wide range of factors interact to create this environment. These factors include well-recognized asthma risk factors that are not specific to the inner city, the structure and delivery of health care, the location and function of the urban environment, and social inequities. In this article, these facets are reviewed, and successful and unsuccessful interventions are discussed, to understand what is needed to solve this problem.

Associations of neighborhood concentrated poverty, neighborhood racial/ethnic composition, and indoor allergen exposures: a cross-sectional analysis of los angeles households, 2006-2008

Although racial/ethnic, socioeconomic, and neighborhood factors have been linked to asthma, and the association between indoor allergens and asthma is well documented, few studies have examined the relationship between these factors and indoor allergens. We examined the frequency of reported indoor allergens and differences by racial/ethnic, socioeconomic, and neighborhood characteristics among a diverse sample of Los Angeles households. Multilevel logistic regression models were used to analyze the data from 723 households from wave 2 of the Los Angeles Family and Neighborhood Survey. The reported presence of rats, mice, cockroaches, mold, pets, and tobacco smoke were the primary outcomes of interest. Hispanic and Asian households had a nearly threefold increase in the odds of reporting cockroaches compared to non-Hispanic Whites (OR, 2.85; 95 % CI 1.38-5.88 and OR, 2.62; 95 % CI 1.02-6.73, respectively) even after adjusting for socioeconomic factors. Primary caregivers who had obtained a high school degree were significantly less likely to report the presence of mice and cockroaches compared to primary caregivers with less than a high school degree (OR, 0.19; 95 % CI 0.08-0.46 and OR, 0.39; 95 % CI 0.23-0.68, respectively). Primary caregivers with more than a high school degree were also less likely to report the presence of rats, mice, and cockroaches within their households, compared to those with less than a high school degree. Compared to renters, home owners were less likely to report the presence of mice, cockroaches, and mold within their households. At the neighborhood level, households located within neighborhoods of high concentrated poverty (where the average poverty rate is at least 50 %) were more likely to report the presence of mice and cockroaches compared to households in low concentrated poverty neighborhoods (average poverty rate is 10 % or less), after adjusting for individual race/ethnicity and socioeconomic characteristics. Our study found evidence in support of neighborhood-level racial/ethnic and socioeconomic influences on indoor allergen exposure, above and beyond individual factors. Future studies should continue to explore individual and neighborhood-level racial/ethnic and socioeconomic differences in household allergen exposures across diverse contexts.

Environmental assessment and exposure reduction of cockroaches: a practice parameter

This parameter was developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Environmental assessment and remediation: a practice parameter." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single person, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion. The findings and conclusions in this manuscript are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention (CDC).

Formaldehyde concentrations in household air of asthma patients determined using colorimetric detector tubes

Formaldehyde is a colorless, pungent gas commonly found in homes and is a respiratory irritant, sensitizer, carcinogen, and asthma trigger. Typical household sources include plywood and particleboard, cleaners, cosmetics, pesticides, and others. Development of a fast and simple measurement technique could facilitate continued research on this important chemical. The goal of this research is to apply an inexpensive short-term measurement method to find correlations between formaldehyde sources and concentration, and formaldehyde concentration and asthma control. Formaldehyde was measured using 30-min grab samples in length-of-stain detector tubes in homes (n = 70) of asthmatics in the Boston, MA area. Clinical status and potential formaldehyde sources were determined. The geometric mean formaldehyde level was 35.1 ppb and ranged from 5 to 132 ppb. Based on one-way ANOVA, t-tests, and linear regression, predictors of log-transformed formaldehyde concentration included absolute humidity, season, and the presence of decorative laminates, fiberglass, or permanent press fabrics (P < 0.05), as well as temperature and household cleaner use (P < 0.10). The geometric mean formaldehyde concentration was 57% higher in homes of children with very poorly controlled asthma compared to homes of other asthmatic children (P = 0.078). This study provides a simple method for measuring household formaldehyde and suggests that exposure is related to poorly controlled asthma.

Performance of dust allergen carpet samplers in controlled laboratory studies

Allergens and other pollutants in house dust are collected using a variety of dust samplers that are assumed to operate similarly. This factorial design study compared sampler performance under controlled environmental conditions. House dust with known particle sizes (212-90, 90-45, and <45 μm) and allergen concentrations were sampled from new carpet squares with varying denier, pile height and pile densities. Dust mass and allergen recovery for total dust mites (Der p 1 and Der f 1), cat (Fel d 1) and cockroach allergen (Bla g 1) were assessed using the Eureka Mighty Mite (EURK), the High Volume Small Surface Sampler (HVS), or the American Industrial Hygiene Association (AIHA) method. Allergen concentrations were quantified using enzyme-linked immunosorbent assays, and dust mass results were corrected for carpet fiber shedding. Samplers were compared by exploring mass collection efficiency (CE=fiber corrected dust mass/applied dust mass) and concentration ratio (CR=allergen concentration in collected sample/allergen concentration in test dust). Test dust allergen concentrations varied by particle size fraction due to varying laboratory performance over time. The EURK and HVS samplers had CEs of 41-63% in the small and medium particle size fractions, and collected less than 20% of the available dust from the large size fraction. The AIHA CE ranged from 10% to 17% in the medium and small particle size fractions, but collected little dust in the largest particle size fraction. The AIHA and HVS samplers were more likely to acquire more representative and less variable allergen CRs compared with the EURK method. Health studies that use allergen concentration as an exposure metric need to consider the implications of sampler performance when interpreting links to health outcomes and development of health-based standards for allergens in house dust.

Assessment of environmental cockroach allergen exposure

In the past, cockroach allergen exposure assessment mainly focused on settled dust in homes in low-income urban cities in the United States. That choice was not wrong; without measureable levels of cockroach allergen, it is difficult to show associations with any home characteristics, much less with health outcomes (e.g., allergy, asthma). However, recent studies in other suburban areas, schools, and other countries have elucidated the importance of cockroach allergen in these environments too. In addition, characterizing the underlying factors that give rise to cockroach allergen exposure (or protect against it) can lead to more targeted public health interventions. This review discusses different approaches to sampling indoor environments, interprets recent asthma and allergy studies, compares cockroach allergen levels from past studies with those of recent studies, and describes strategies for decreasing exposures.

Challenges in providing preventive care to inner-city children with asthma

Although the scientific understanding of the pathophysiology of asthma and the quality of asthma therapies have significantly improved over the past 30 years, asthma morbidity remains high and preventive care low for inner-city children. This article focuses on 4 major challenges to providing preventive care (family and patient attitudes and beliefs, lack of access to quality medical care, psychosocial factors, environmental factors) based on prior evidence and the authors' observation of these challenges in research with inner-city children with asthma over the past decade. Cost issues related to preventive care are addressed, and recommendations provide for pediatric nurses.

Cockroach allergens induce biphasic asthma-like pulmonary inflammation in outbred mice

OBJECTIVES

The aim of this study is to define the kinetics of the pulmonary inflammatory response in cockroach allergen (CRA) sensitized and challenged outbred mice.

METHODS

Asthma-like pulmonary inflammation was induced with three pulmonary exposures to CRA, without the use of adjuvants. Mice were sacrificed at multiple time points and asthma-like pulmonary inflammation quantified.

RESULTS

Several pulmonary parameters showed a pronounced biphasic inflammatory response with an early stage (1.5 hours post challenge) and late stage (24 hours). The initial phase was characterized by the production of multiple inflammatory mediators, including CXC chemokines, and the recruitment of neutrophils to the lung. The number of pulmonary eosinophils decreased in the early phase but quickly rebounded. Both the early and late phases had increases in TNF production in addition to airways hyperreactivity. The model also demonstrated early production of mucin with clearance by 12 hours followed by new accumulation of mucin in the pulmonary epithelial cells. Eotaxins within the lung peaked at about 12 hours and the numbers of eosinophils in the lung remained constant throughout the 48 hours of the study.

CONCLUSIONS

The pulmonary inflammatory parameters in response to a clinically relevant allergen define a biphasic response. These data may be used to investigate the pathogenesis of the disease and develop targeted therapies for the distinct phases.

Prevention and treatment of DNA vaccine encoding cockroach allergen Bla g 1 in a mouse model of allergic airway inflammation

BACKGROUND

One-fourth of the US population is sensitized to the German cockroach. Primary German cockroach allergen Bla g 1 is detected in 63% of homes and 52% of childcare facilities in the United States. No effective treatment or vaccination strategies are yet available.

OBJECTIVES

We evaluated the prophylactic and therapeutic efficacy of a plasmid DNA-mediated vaccination using the Bla g 1 gene in a mouse model of allergic inflammatory airway disease.

METHODS

A plasmid DNA vector coding for the Bla g 1 allergen controlled by cytomegalovirus promoter was constructed. To estimate the protective efficacy, BALB/c mice were given three injections of plasmid DNA-Bla g 1 prior to sensitization with two priming doses of recombinant Bla g 1 (rBla g 1) antigens, followed by nebulized rBla g 1 challenge. In the therapeutic approach, sensitization was followed by administering Bla g 1 DNA vaccine.

RESULTS

Bla g 1 vaccination significantly reduced allergen-induced airway inflammation, even after mice were presensitized and a Th2-dominant response was established. The Bla g 1 vaccination significantly reduced total inflammatory cell infiltrate, eosinophilia, secretion of Th2 cytokines IL-4 and IL-5 in bronchoalveolar lavage fluid, allergen-induced inflammatory infiltrates in the lungs, and Bla g 1-specific IgE in serum upon challenge with rBla g 1. Importantly, Bla g 1 DNA vaccination was able to induce IL-10-secreting regulatory T cells that could suppress the allergen-specific Th2 cells.

CONCLUSION

DNA vaccination showed protective and therapeutic efficacy against a clinically relevant allergen Bla g 1.

Does allergen avoidance work?

Allergic rhinitis affects a large portion of the population. Patients are frequently sensitized to indoor allergens. The most important contributors are house dust mites, pets, and fungi. In very controlled environments where allergen exposure is significantly reduced, individuals have been shown to have clinical improvement in allergic rhinitis and/or asthma symptoms. Achieving sufficient exposure reduction in the home has proven difficult. Nonetheless, evidence exists that demonstrates exposure avoidance can be useful as an adjunct to other therapies, such as pharmacotherapy and immunotherapy, for the treatment of allergic rhinitis.

Moving environmental justice indoors: understanding structural influences on residential exposure patterns in low-income communities

OBJECTIVES

The indoor environment has not been fully incorporated into the environmental justice dialogue. To inform strategies to reduce disparities, we developed a framework to identify the individual and place-based drivers of indoor environment quality.

METHODS

We reviewed empirical evidence of socioeconomic disparities in indoor exposures and key determinants of these exposures for air pollutants, lead, allergens, and semivolatile organic compounds. We also used an indoor air quality model applied to multifamily housing to illustrate how nitrogen dioxide (NO(2)) and fine particulate matter (PM(2.5)) vary as a function of factors known to be influenced by socioeconomic status.

RESULTS

Indoor concentrations of multiple pollutants are elevated in low-socioeconomic status households. Differences in these exposures are driven by the combined influences of indoor sources, outdoor sources, physical structures, and residential activity patterns. Simulation models confirmed indoor sources' importance in determining indoor NO(2) and PM(2.5) exposures and showed the influence of household-specific determinants.

CONCLUSIONS

Both theoretical models and empirical evidence emphasized that disparities in indoor environmental exposure can be significant. Understanding key determinants of multiple indoor exposures can aid in developing policies to reduce these disparities.

Longterm persistence of proteolytic activities in frass of Blattella germanica increases its allergenic potential

Chromogenic microplate assays in 96 wells were used to determine the stability of enzyme activity in frass of Blattella germanica (Blattodea: Blattellidae). Frass samples were exposed to controlled conditions [temperature 15-35 °C and/or 53-100% relative humidity (RH)] and to household conditions (apartment). Exposure times were 0 (control), 90, 183 and 276 days. Starch digestion and cellulolytic activities decreased during exposure. Non-specific proteolytic activities were affected by changes in selective proteolytic activities. Activities towards AAPpNA and SA(3) pNA strongly increased at 100% RH, indicating the possible influence of microorganisms growing on frass. Activities towards BApNA and ArgpNA decreased with increasing decomposition time, whereas activity towards ZRRpNA was not influenced by exposure time. The largest decrease in activities towards ArgpNA and BApNA occurred at temperatures of 15 °C, 30 °C and 35 °C and at 100% RH. Activities towards BApNA and ZRRpNA were very stable under different temperature and RH conditions; this was confirmed by findings showing that these activities were stable in the experimental apartment. In comparison with the control, activities towards ZRRpNA and BApNA after 276 days decreased by 1% and 19%, respectively. The longterm persistence of proteolytic activities in cockroach frass increases their allergenic hazard potential.

The National Asthma Survey--New York State: association of the home environment with current asthma status

OBJECTIVES

The National Asthma Survey--New York State (NYS), a telephone survey of NYS residents, was conducted in 2002-2003 to further understand the burden of asthma among adults and children and to identify health, socioeconomic, behavioral, and environmental factors associated with asthma.

METHODS

A total of 1,412 households with at least one member with current asthma and 2,290 control households answered questions about their home environment (e.g., presence of asthma triggers and practices that promote or reduce common asthma triggers). RESULTS; For children younger than 18 years of age, we found statistically significant positive associations between current asthma and the presence of mold (adjusted odds ratio [AOR] = 2.1, 95% confidence interval [CI] 1.3, 3.3), air cleaners (AOR = 1.5, 95% CI 1.1, 2.1), dehumidifiers (AOR = 2.0, 95% CI 1.4, 2.7), and humidifiers (AOR = 1.6, 95% CI 1.1, 2.3). For adults, there were statistically significant positive associations with the presence of mold (AOR = 2.5, 95% CI 1.8, 3.4), air cleaners (AOR = 2.2, 95% CI 1.7, 2.8), and humidifiers (AOR = 1.4, 95% CI 1.1, 1.8). There were no statistically significant associations with the presence of cockroaches, pets, or tobacco smoke, while use of a wood-burning stove or fireplace was significantly more prevalent in control homes.

CONCLUSIONS

Asthma guidelines emphasize the importance of reducing triggers in the home as part of a multifaceted approach to asthma control. Despite these guidelines, many asthma triggers (specifically, mold) were as prevalent or more so in the homes of New Yorkers with asthma as compared with control households. Public health interventions in NYS should focus on educating households about potential asthma triggers and their sources and teach methods to prevent, reduce, or eliminate them.

Do questions reflecting indoor air pollutant exposure from a questionnaire predict direct measure of exposure in owner-occupied houses?

Home characteristic questions are used in epidemiological studies and clinical settings to assess potentially harmful exposures in the home. The objective of this study was to determine whether questionnaire-reported home characteristics can predict directly measured pollutants. Sixty home inspections were conducted on a subsample of the 2006 population-based Toronto Child Health Evaluation Questionnaire. Indoor/outdoor air and settled dust samples were analyzed. Mean Fel d 1 was higher (p < 0.0001) in homes with a cat (450.58 μg/g) versus without (22.28 μg/g). Mean indoor NO(2) was higher (p = 0.003) in homes with gas stoves (14.98 ppb) versus without (8.31 ppb). Self-reported musty odours predicted higher glucan levels (10554.37 μg/g versus 6308.58 μg/g, p = 0.0077). Der f 1 was predicted by the home's age, but not by reports of carpets, and was higher in homes with mean relative humidity > 50% (61.30 μg/g, versus 6.24 μg/g, p = 0.002). Self-reported presence of a cat, a gas stove, musty odours, mice, and the home's age and indoor relative humidity over 50% predicted measured indoor levels of cat allergens, NO(2), fungal glucan, mouse allergens and dust mite allergens, respectively. These results are helpful for understanding the significance of indoor exposures ascertained by self-reporting in large epidemiological studies and also in the clinical setting.